As for FastCGI, although it is language agnostic it didn't really get traction outside of PHP.

Pro tip: WSGI is pronounced like "whiskey". :-)

One of the initial inspirations for creating the Django web framework back a the Lawrence Journal-World newspaper in ~2003 was that we wanted to start using Python on the web, but were concerned that mod_python didn't have quite enough existing users.

What if it turned out not to work for us?

So we designed a simple abstraction layer - a request and response object - as an insurance policy. If mod_python turned out not to work for us we could switch to something else without having to rewrite all of our code.

At around about the same time the Python Web SIG formed - https://simonwillison.net/2003/Oct/18/pythonWebSIG/ - and we joined it with the aim of helping define a standard similar to what we had been building for our own, private newspaper CMS.

WSGI was the eventual result of that SIG - I didn't participate in the working group nearly as actively as I had planned to, so I can't say that I had much if any impact on the result.

But hopefully this illustrates that yes, the people involved were very aware of mod_python back in 2003 when this work kicked off.

The point of WSGI is for the server and application to speak the same python-level protocol. You can have a wsgi adapter on top of fcgi, though it’s really a waste of resources if you can skip fcgi entirely (which you usually can).